Ground anchor



FIG. 1 is a perspective view of my design for a ground anchor as seen from the bottom end;

FIG. 2 is a perspective view of my design for a ground anchor as seen from the top end;

FIG. 3 is a front view of my design for a ground anchor; and,

FIG. 4 is a rear view of my design for a ground anchor, the left and right side views being shown in the perspective views. 

I claim the ornamental design for a ground anchor, as shown and described. 